Silver electromigration (i.e., Ag dendrite) is primarily a direct current phenomenon. Dendrite growth appears as a fern like growth along a surface. Silver dendrite growth requires available silver (exposed silver), a migration medium (moisture), an electric field (gate-source voltage), and a surface (such as beryllium oxide (BeO)).
Silver can electromigrate under non-condensing but humid conditions (i.e., humid electromigration). The rate of electromigration increases directly with relative humidity. In some cases, the moisture needed for electromigration is just a few monolayers of moisture. The positively charged ions of the silver metal move under the influence of an electric field through the moisture paths on the insulator toward the negative conductor where the ions are reduced back to silver metal.